Ligluefied-am-conveying conduit



No. 625,759. Patented May 30, 1899 E. C. HARGRAVE.

LlflUEE-"IED AIR CONVEYING CONDUIT Application filed July 26, 1898.)

(N0 Modei.)

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Ll QUEFlED fillR GGNVEYENG CGNDUlT.

srnorrroarron forming part or Letters l atent No. 625,759, dated May 30,mos.

. Application nu July 26, met.

To' all whom it may concern.-

Be it known that I, EDWARD'C. HARGRAVE, aciti zen of the United States,residing at Bay City, in the county of Bay and State of Michigen, haveinvented new and useful Improvements in Liquefied-Ah"-ConveyingConduits, of which the following is a specification.

This invention relates to the art of utilizing liquefied air or gas forcooling or 'refrig' rooms, or other spaces where a low temperature isdesired for preserving perishable articles or-for refrigerating purposesin general. The llIVBDlJlOlLOOflSlSlJS of the process and apparatushereinafter described, and set forth in the claims.

In the drawing, the figure represents in sec tional elevation thestructural embodiment of my invention which seemsat this time to be thepreferable one. I

In order to enable those skilled in the art to make and use myinvention, I will now describe the same in. detail, reference being madeto the accompanying'drawing, wherein the numeral 1 indicates a reservoiror tank containing liquefiedair or gas obtained, as is known, byreducing air or gas to a liquid V state through the medium of high.pressure and reduction of temperature. The reservoir or tank connects bya pipe 2 with a liquidforcing steam-pump 3 or any other pump which willserve to. force the liquefied air through the piping, hereinafterexplained, if the liquid requires to be elevated. The'pipingforconveyingthe liquefied air from the pump to a more or'less distant point orfrol'n one apartment or room of a building to another apartment or roomis represented as first rising vertically, as at 4, from thepumpcylinder, and thence extending horizontally, as at 5, through theapartmentsor rooms of the building to the place or point where theliquefied air is to be utilized for refrigerating or other purposes. Thepiping-'4 5 maybe composed of ordinary metal tubes, and it is completelyenveloped orsurrounded by a nononduoting casing 6, preferably so appliedrelatively to the exterior of the piping as to create or provide asurrounding space hei tween its inner side and the exterior of the Ipiping for a purpose which will hereinafter crating apartments,chambers, refrigerators,

Berisl No. 686,832. (No model.)

appear. The casing is preferably coinposed of felt or rock-wool; but itmay be made of any other suitable non-conducting material or substance.This casing excludes the out bursting of the latter, while theuon-couduct' ing casing excludes the heated atmosphere are from thesurface of the piping, reduces the temperature of the latter, andmaintains the liquefied air in the piping in a liquid state, except asto the portions which naturally evaporate. The evaporated liquefied gasin the form of a vapor is preferably conducted by short tubes 10 fromthe safety-valves into-the space between the inner side of thenon-couducting casing and the exterior of the piping or the purpose ofcooling the latterand aiding in maintaining the liquefied gas flowing orpassing through such piping in a liquefied state. I. do not wish to beunderstood, how

ever, as confining myself to conducting the evaporated liquefied gasfrom the safetyvalves to a. space betweeuthe non-conducting casing andthe exterior of the piping; nor do I confine myself to so arranging thenon-conducting casing relatively to the surface of the piping that thereis a surrounding space he tween the same. The non-conducting casing maybe placed in direct contact with the piping, and the evaporatingliquefied air may pass away after escaping from the safety-valves or beutilized for cooling purposes.

By the construction described it will be observed that the evaporatingair or gas in the pipe 4 5 is allowed to escape therefrom in suiiicie-ntquantities and is utilized to maintain.theremaiuing air or gas thereinin a liquefied state, and thereby prevent undue pressure within saidpipe.

The pump for forcing the liquefied air or gas through the conduit to theplace or point desired may be dispensed with lifthe lique IOU mam mabove aim ievni (if the com wiii be Qbvioiis.

I v m; iiius described. my izi'a-eniion, what 1i. process conductingliquefied air in: mm me poini; i9 another, which com EiP S iii pipingthe game, aiiswing a puiiipu .iiifli in evzipmzite, in quantitiessufficient main tain the main body of the air or gas in iiqueiieii stateand thereby {mavens undue iiiwi'efi'om. 2, The process of onductmgiiquened air m" 1" mm one point to another, which consiaiiis in piping;the same, allowing a, portion iimraof t0 evaporate and conveying theevagiamted portion through an annular space zii'mmfl'the main body ofthe air or gas in qiismiibies SliffiCiBD'fi to maintain said body iniiqiieiied state and thereby prevent undue iiiifiifiiil'fi therefrom.

A mmiuit for liquefied aii' 0r gas, provided with means fmpermit-tingthe escape 05f ev'iigiin-aiing iii! 92? gas; from the integioriiiwieOfi-in Slfi"i8nir(} i1iifli|iiiy to maintain the air 0: i quid insaid cenduit and thereby undue strain thereof.

o liquefied air or gas comoncomiuciing sui'idund 1;, and ferpcrxxaii-ting piping, in suificient quantity to maintain the air 01* gasliquid in. aid piping and thereby permitting iiia escape of Umevaporating air or gas from said piping in sufficiezit quantitytomaintain the air or gas liquid. in said. piping and thereby pi'cveni;undue strain ilhfiififfif v 6. Tim combination with piping for couveyingliquefied air 0r gas fmnione place to another, of a casingreiaitiveiygrranged to the exterriai surface of the piping tu'provide acontinuous intarvening space, regulatingvaives connected with 011%piping at different points for permitting the escape of the evaporatingair 01' gas from the interior of the piping to. the intervening space in'snffieient quantity is maintz iii the air 0r gas liquid in said pipingand thereby prvent; undue: strain thereof,

In testimony whereof I have hereunto-set my hand in presence of twosubscribing witnesses.

EDWARD G. HARG-RAVE. Witnesses:

ALBERT H. N'onms, F. ii KEEFER.

